The effect of pre-deformation on corrosion resistance of the passive film formed on 2205 duplex stainless steel

Effect of pre-deformation on the corrosion resistance of 2205 duplex stainless steel was investigated by microstructure observations, electronic work function measurement and electrochemical experiments. Transmission electron microscope observations showed that the dislocation density in ferritic and austenitic phases increased with the increasing of strain. Moreover, the strain induced α′-martensite was observed in sample with large strain based on XRD analysis and Transmission electron microscope observations. The electron work function of ferrite was higher than that of austenite. In addition, the surface electron work function of ferritic and austenitic phases decreased with the increasing of strain. More dislocations and chloride ions promoted to form more oxygen vacancies and cation vacancies in the passive film based on point defect model and autocatalytic reaction. Therefore, the corrosion resistance of the passive film formed on 2205 duplex stainless steel decreased with the increasing of strain in borate buffer solution with chloride ions. These results were proven by further immersion test.